Spinal stabilization system to flexibly connect vertebrae

Abstract

A surgically implanted spinal stabilization system uses posterior anchor hooks attached to vertebrae to retain elastic bands to retain flexibility and mobility while maintaining alignment and preventing excessive motion and deformity. The elastic bands may parallel the longitudinal axis of the spine, or, for enhanced promotion of alignment, they may also arranged in a diagonally crossing configuration. Multi-level fixation can be achieved using the spinal stabilization system with longer elastic bands. A method of applying the spinal stabilization system using an elastic band application tool facilitates simple, rapid application of the system to a patient.

1 . A system for flexibly connecting at least two vertebrae comprising: 
 at least one pair of anchor hooks attachable to the at least two vertebrae to be flexibly connected; and    at least one elastic band retained by the at least one pair of anchor hooks.    
   
   
       2 . The system of  claim 1 , wherein: 
 the at least two vertebrae to be flexibly connected comprise: 
 an upper vertebra; and  
 an adjacent lower vertebra of a spine having a longitudinal axis;  
   the at least one pair of anchor hooks comprise: 
 a first left anchor hook and a first right anchor hook attachable to the upper vertebra; and  
 a second left anchor hook and a second right anchor hook attachable to the lower vertebra; and  
   the at least one elastic band comprises: 
 a first elastic band retained by the first left anchor hook in the upper vertebra and the second left anchor hook in the lower vertebra, wherein the first elastic band is substantially parallel to the longitudinal axis of the spine; and  
 a second elastic band retained by the first right anchor hook in the upper vertebra and the second right anchor hook in the lower vertebra, wherein the second elastic band is substantially parallel to the longitudinal axis of the spine.  
   
   
   
       3 . The system of  claim 2 , further comprising: 
 a third elastic band retained by the first left anchor hook in the upper vertebra and the second right anchor hook in the lower vertebra; and    a fourth elastic band retained by the first right anchor hook in the upper vertebra and the second left anchor hook in the lower vertebra.    
   
   
       4 . The system of  claim 2 , wherein the first and second anchor hooks attachable to the upper and lower vertebrae each comprises a crimpable hook section affixed to a screw thread, and wherein the crimpable hook section further comprises a recess where the crimpable hook section meets the screw thread and a tapered tip opposite where the crimpable hook section meets the screw thread.  
   
   
       5 . The system of  claim 4 , wherein the first and second anchor hooks attachable to the upper and lower vertebrae further comprise a groove in the crimpable hook section configured to interface with an elastic band application tool.  
   
   
       6 . The system of  claim 2 , wherein the elastic bands further comprise a continuous radio opaque stripe.  
   
   
       7 . The system of  claim 2 , wherein the elastic bands are comprised of reinforced silastic material.  
   
   
       8 . The system of  claim 2 , wherein the elastic bands are of a length corresponding to a region of the spine in which the upper and lower vertebrae are located.  
   
   
       9 . The system of  claim 2 , wherein the elastic bands have a resistance to extension corresponding to a desired flexion capacity of the upper and lower vertebrae.  
   
   
       10 . The system of  claim 9 , wherein the elastic bands have a thickness proportional to the resistance to extension.  
   
   
       11 . The system of  claim 9 , wherein the resistance to extension of the elastic bands is defined by an internal variation in resistance.  
   
   
       12 . The system of  claim 9 , wherein the elastic bands further comprise color coding representing the resistance to extension.  
   
   
       13 . The system of  claim 2 , wherein the first and second anchor hooks are comprised of titanium material.  
   
   
       14 . The system of  claim 2 , wherein each anchor hook is of a size appropriate to the vertebra to which it is attached.  
   
   
       15 . A system for flexibly connecting an upper vertebra, a lower vertebra, and at least one intermediate vertebrae of a spine having a longitudinal axis comprising: 
 a first left anchor hook and a first right anchor hook attachable to the upper vertebra;    a second left anchor hook and a second right anchor hook attachable to the lower vertebra;    a third left anchor hook and a third right anchor hook attachable to each of the at least one intermediate vertebrae;    a first elastic band retained by the first left anchor hook in the upper vertebra, the third left anchor hooks in the at least one intermediate vertebrae, and the second left anchor hook in the lower vertebra, wherein the first elastic band is substantially parallel to the longitudinal axis of the spine; and    a second elastic band retained by the first right anchor hook in the upper vertebra, the third right anchor hooks in the at least one intermediate vertebrae, and the second right anchor hook in the lower vertebra, wherein the second elastic band is substantially parallel to the longitudinal axis of the spine.    
   
   
       16 . The system of  claim 15 , wherein the anchor hooks attachable to the upper and lower vertebrae each comprise a crimpable hook section affixed to a screw thread, and wherein the anchor hooks attachable to each of the at least one intermediate vertebrae each comprise two crimpable hook sections affixed to a screw thread, and wherein the crimpable hook sections of the anchor hooks for upper, lower, and intermediate vertebrae each further comprise a recess where the crimpable hook section meets the screw thread and a tapered tip opposite where the crimpable hook section meets the screw thread.  
   
   
       17 . The system of  claim 15 , further comprising at least one pair of diagonal crossing elastic bands wherein one of each of the at least one pair of diagonal crossing elastic bands is retained by the right anchor hook in a flexibly connected vertebra and the left hook in an adjacent flexibly connected vertebra and the other of each of the at least one pair of diagonal crossing elastic bands is retained by the left anchor hook in said flexibly connected vertebra and the right anchor hook in said adjacent flexibly connected vertebra.  
   
   
       18 . The system of  claim 17 , wherein the anchor hooks attachable to the upper and lower vertebrae each comprise a crimpable hook section affixed to a screw thread, and wherein the anchor hooks attachable to each of the at least one intermediate vertebrae each comprise at least two crimpable hook sections affixed to a screw thread, and wherein the crimpable hook sections of the anchor hooks for upper, lower, and intermediate vertebrae each further comprise a recess where the crimpable hook section meets the screw thread and a tapered tip opposite where the crimpable hook section meets the screw thread.  
   
   
       19 . The system of  claim 15 , wherein the anchor hooks attachable to the upper, lower, and intermediate vertebrae further comprise a groove in the crimpable hook section configured to interface with an elastic band application tool.  
   
   
       20 . The system of  claim 15 , wherein the elastic bands further comprise a continuous radio opaque stripe.  
   
   
       21 . The system of  claim 15 , wherein the elastic bands are comprised of reinforced silastic material.  
   
   
       22 . The system of  claim 15 , wherein the elastic bands are of a length corresponding to the distance between the two anchor hooks that retain the elastic band.  
   
   
       23 . The system of  claim 15 , wherein the elastic bands have a resistance to extension corresponding to a desired flexion capacity of the upper, lower, and intermediate vertebrae.  
   
   
       24 . The system of  claim 23 , wherein the elastic bands have a thickness proportional to the resistance to extension.  
   
   
       25 . The system of  claim 23 , wherein the resistance to extension of the elastic bands is defined by an internal variation in resistance.  
   
   
       26 . The system of  claim 23 , wherein the elastic bands further comprise color coding representing the resistance to extension.  
   
   
       27 . The system of  claim 15 , wherein the anchor hooks are comprised of titanium material.  
   
   
       28 . The system of  claim 15 , wherein each anchor hook is of a size appropriate to the vertebra to which it is attached.  
   
   
       29 . A method of applying a spinal stabilization system to a spine of a person comprising the steps of: 
 drilling two pilot holes in each vertebra to be flexibly connected;    applying an anchor hook to each pilot hole in the vertebrae to be flexibly connected;    applying elastic bands to the anchor hooks; and    crimping the anchor hooks to retain the elastic bands;    
   
   
       30 . The method of  claim 29 , wherein the step of applying elastic bands to the anchor hooks further comprises the steps of: 
 using an elastic band application tool comprising two pivotable lever arms, an anchor hook interface, a locking mechanism, and an elastic band rolling mechanism to extend the band over the anchor hooks, wherein the anchor hook interface of the elastic band application tool mates with a groove on each of the anchor hooks to which an elastic band is applied; and    releasing the elastic band from the elastic band application tool onto the anchor hooks.